Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09G—POLISHING COMPOSITIONS; SKI WAXES
  • C09G1/00—Polishing compositions
  • C09G1/02—Polishing compositions containing abrasives or grinding agents
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
  • C09K3/1436—Composite particles, e.g. coated particles
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
  • C09K3/1454—Abrasive powders, suspensions and pastes for polishing
  • C09K3/1463—Aqueous liquid suspensions
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
  • H01L21/3205—Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers
  • H01L21/321—After treatment
  • H01L21/32115—Planarisation
  • H01L21/3212—Planarisation by chemical mechanical polishing [CMP]

Definitions

• the present invention relates to a polishing composition which can be used in the semiconductor industry. More particularly, the present invention relates to use of Al 2 O 3 /SiO 2 composite particles as an essential abrasive so as to improve the removal rate without causing microscratches.
• highly integrated semiconductor devices are manufactured by alternately depositing conducting materials and insulating materials and thus forming patterns. If a surface is not flat, it is very difficult to form a new pattern on the surface. To highly integrate semiconductor devices, it is required to minimize feature sizes and to perform multilevel interconnections. Global planarization is one of the most important prerequisites to achieve this.
• planarization methods ever known, CMP is the most effective.
• the other planarization methods which have been developed thus far such as SOG/Etch Back/ECR Depo & Etch, are very complicated in process procedure, requiring 2-5 process steps, but the CMP process can be finished simply by polishing and cleaning.
• polishing compositions or slurries for use in semiconductor CMP processes commonly comprise metallic oxide. According to the materials to be polished, the conventional polishing compositions or slurries can be largely classified into three kinds: polishing compositions for monosilicon, for insulating layers, and for metal lines and plugs.
• Abrasives which are most extensively used in the semiconductor CMP process are silica (SiO 2 ), alumina (Al 2 O 3 ), ceria (CeO 2 ), zirconia (ZrO 2 ), and titania (TiO 2 ), which can be produced by a fuming or a sol-gel method, as described in U.S. Pat. Nos. 4,959,113, 5,354,490, and 5,516,346 and WO 97/40,030.
• Mn 2 O 3 mangania
• SiN silicon nitride
• a polishing slurry comprising silica causes less microscratches compared with a polishing slurry comprising alumina, but shows a low removal rate against barrier material when being applied as a metal slurry.
• a polishing slurry comprising alumina is advantageous in terms of being more stable in a dispersed state compared with a polishing slurry comprising silica and high in the removal rate against barrier materials, but suffers from a serious disadvantage of causing a quantity of microscratches after polishing.
• polishing slurries comprising ceria, zirconia, titania, mangania or silicon nitride have not yet been stably established in the production processes on a commercial scale and are expensive compared with ones comprising silica or alumina.
• a polishing composition comprising fine Al 2 O 3 /SiO 2 composite-based metal oxide particles, deionized water and additives.
• the polishing composition of the present invention is suitable for use in polishing various industrial products, including semiconductors, photomasks, glassdiscs, and synthetic resins, especially, in surface planarization of device wafers.
• various industrial products including semiconductors, photomasks, glassdiscs, and synthetic resins, especially, in surface planarization of device wafers.
• the polishing composition of the present invention can find numerous applications in CMP fields, especially in highly integrated device fabrication fields, including the polishing of silicon, interlayer insulating films, metal lines and plug, and barrier materials.
• the present invention contemplates use of an Al 2 O 3 /SiO 2 composite as an essential metal oxide ingredient of a CMP composition suitable for use in fabricating semiconductor devices.
• the Al 2 O 3 /SiO 2 composite can be prepared from AlCl 3 and SiCl 4 by a Co-Fuming method as follows: AlCl 3 + SiCl 4 ⁇ ⁇ Heat ⁇ ⁇ ( ⁇ ⁇ 1000 ⁇ ° ⁇ ⁇ C . ) air ⁇ Al 2 ⁇ O 3 / SiO 2 + HCl .
• the metal oxide particles thus obtained are not in a simple mixed state of Al 2 O 3 and SiO 2 , but in a composite state in which Al 2 O 3 is linked to SiO 2 .
• the composite shows characteristic phisycal properties which are quite different from a simple mixture of the two components. Physical properties of the Al 2 O 3 /SiO 2 composite based on ‘VP MOX 90’, a brand name of Degussa, Germany, are summarized in Table 1, below.
• each component in the composite can be controlled depending on fed amount and reaction condition.
• a composite comprising 67 ⁇ 15 wt % of Al 2 O 3 and 33 ⁇ 15 wt % of SiO 2 is obtained, which is preferable for the present invention.
• any of the conventional dispersion methods such as high speed milling with a dyno-mill or ball mill and use of a high shear mixer, is available to prepare a dispersion of Al 2 O 3 /SiO 2 for use in a polishing composition. More efficient than conventional methods is the method using a microfluidizer, disclosed in Korean Pat. Appl'n No. 98-39212 filed by the present inventors.
• the Al 2 O 3 /SiO 2 composite is in primary particle size between 10 and 100 nm and preferably between 20 and 60 nm as measured in BET.
• the primary particle size is smaller than 10 nm, a sharp decrease occures in the removal rate, deteriorating the throughput.
• the primary particle size is larger than 100 nm, an increased removal rate is obtained, but difficulty is imposed on the dispersion of the particles. What is worse, a quantity of large particles are feasible to cause a significant quantity of microscratches.
• the metal oxides in an aqueous dispersion form secondary particles, which preferably range, in mean size, from 10 to 500 nm. Particles larger than 500 nm in size negatively affect the dispersion stability such that the aqueous dispersion suffers sedimentation after being allowed for stand for one week at room temperature. Thus, a stirring process is additionally conducted just before a CMP process.
• the Al 2 O 3 /SiO 2 composite of the present invention also should meet a specific surface area requirement which is in the range of 20-200 m 2 /g.
• the solid content of the Al 2 O 3 /SiO 2 it is on the order of 1-50% by weight based on the total weight of the polishing composition and preferably on the order of 1-25% by weight.
• the solid content of Al 2 O 3 /SiO 2 is below 1% by weight, desired effects cannot be obtained.
• the solid content of Al 2 O 3 /SiO 2 may be further confined to a narrower range depending on the surfaces to be polished.
• the polishing composition using the Al 2 O 3 /SiO 2 as a main abrasive more preferably has a solid content of 1-5% by weight for monosilicon, 5-15% by weight for interlayer insulating films, and 3-7% by weight for metal lines, plugs, and barrier materials.
• the polishing dispersion may be further supplemented with additives depending on the substrates to be polished.
• the dispersion may be added with bases such as KOH for polishing monosilicons and interlayer insulating films and with oxidizing agents or other appropriate agents for polishing metal surface such as W and Cu, and barrier materials such as Ti/TiN and Ta/TaN.
• bases such as KOH for polishing monosilicons and interlayer insulating films and with oxidizing agents or other appropriate agents for polishing metal surface such as W and Cu, and barrier materials such as Ti/TiN and Ta/TaN.
• bases include KOH, NH 4 OH, and R 4 NOH. Acids also can be added, which can be exemplified by H 3 PO 4 , CH 3 COOH, HCl, HF and so on.
• supplementary oxidizing agents are H 2 O 2 , KIO 3 , HNO 3 , H 3 PO 4 , K 2 Fe(CN) 6 , Na 2 Cr 2 O 7 , KOCl, Fe(NO 3 ) 2 , NH 2 OH, and DMSO.
• Divalent acids such as oxalic acid, malonic acid and succinic acid can be used as additives for the polishing composition of the present invention.
• potassium hydrogen phthalate may be used.
• 2-pyrrolidinone may be added to enhance a moisturizing effect, thereby preventing the aggregation and agglomeration of the abrasive particles. These additives may be used alone or in combination.
• the addition order of the additives is not particularly limited. They may be added before or after the dispersion of the Al 2 O 3 /SiO 2 composite in deionized water.
• the polishing composition of the present invention is essentially composed, by weight, of 1-50% of the Al 2 O 3 /SiO 2 composite, 1-10% of the additives, and 40-98% of deionized water.
• the present invention is directed to a polishing composition comprising fine Al 2 O 3 /SiO 2 composite particles, which can polish semiconductor wafers at high removal rates and show high selectivity for interlayer insulating films (SiO 2 ) without causing microscratches after polishing. Therefore, the present invention can be applied to the fabrication of highly integrated devices, such as shallow trench isolation (STI) processes.
• STI shallow trench isolation
• Example II The same procedure as in Example I was repeated, except that an interlayer insulating film (SiO 2 ) and an SiN film were independently used instead of the monosilicon substrate.
• an interlayer insulating film (SiO 2 ) and an SiN film were independently used instead of the monosilicon substrate.
• Polishing slurries were prepared and evaluated for polishing performance in the same manner as in Example I, except that the following metal oxide materials were used instead of the Al 2 O 3 /SiO 2 composite dispersion.
• Al 2 O 3 dispersion slurry particle size distribution 10-720 nm, mean size: 255 nm
• SiO 2 dispersion slurry particle size distribution 10-400 nm, mean size: 175 nm
• CeO 2 dispersion slurry particle size distribution 10-1100 nm, mean size: 450 nm
• Polishing slurries were prepared and evaluated for polishing performance in the same manner as in Example II, except that the following metal oxide materials were used instead of the Al 2 O 3 /SiO 2 composite dispersion.
• Polishing slurries were prepared and evaluated for polishing performance in the same manner as in Example III, except that the following metal oxide materials were used instead of the Al 2 O 3 /SiO 2 composite dispersion.
• Polishing slurries were prepared and evaluated for polishing performance in the same manner as in Example IV, except that the following metal oxide materials were used instead of the Al 2 O 3 /SiO 2 composite dispersion.
• the polishing composition of the present invention is superior in removal rate and free of causing microscratches after polishing and suitable for use in the global planarization of device wafer surfaces.

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• 1999
  • 1999-11-12 KR KR1019990050159A patent/KR20010046395A/ko not_active Application Discontinuation
• 2000
  • 2000-06-20 TW TW89112062A patent/TW573000B/zh not_active IP Right Cessation
  • 2000-06-22 US US09/598,768 patent/US6447694B1/en not_active Expired - Lifetime
  • 2000-06-29 CN CNB001095250A patent/CN1171963C/zh not_active Expired - Lifetime
  • 2000-08-01 JP JP2000233384A patent/JP2001139935A/ja active Pending

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